Best Sanitizer For Exposed Spa

[Donaldor]

Wow. Great forum here. Thanks for all the posts here.

I'm frustrated with sanitizing my exposed spa (in-ground Rock-Spa) which sees sunlight most of the day (SoCal). I started with the LeasureTime Bromine product which was OK but had some algae problems in the summer. Also had issues with I'm guessing chlorine gas being released when jets (bubbles) were on making it difficult to breathe near the water's surface.

Am currently using Brilliance System. Like the lack of chlorine smell plus no more breathing problems. However its nearly impossible to maintain free bromine without oxydizing every 2-3 days when the sun is shining - and we haven't even hit summer yet! Turning out to be very expensive.

I guess I need a more sunlight-stable system. Should I switch to a chlorine only system in this case? We use the spa about every 3 days or so. No small kids in it either. Can you advise proper start-up & maintenance procedures as well? We have hard water here so I always seems to be battling a scale ring as well.

Got the tip about the test kit vs strips. Will do that ASAP.

Thanks in advance for your input.

[waterbear]

but had some algae problems in the summer.

If you had algae then you were letting your bromine levels drop too low or the bromine was getting burned off by the sun too quickly. If you keep your bromine in the 6-8 ppm range and test it daily you should be able to avoid that problem. Shocking, or oxidizing, the water to raise the bromine above 10 ppm weekly helps but be sure to let the bromine drop below 10 ppm before entering the spa.

Also had issues with I'm guessing chlorine gas being released when jets (bubbles) were on making it difficult to breathe near the water's surface.

If you were using bromine then there would not be chlorine in the spa, even if you just shocked with chlorine, if you have first establised a bromide reserve in the water by adding sodium bromide on filling. The chlorine would have oxidized the bromide into active bromine sanitizer, hypobromous acid, and would no longer exists in the water. Bromine has a decided 'chemical' or 'caustic' smell that many people find unpleasant. I suspect that is what you were smelling and I suspect that your bromine levels were high at the time also. If you were actually smelling chlorine it would mean that there was no bromide reserve in the water (which sometimes happens when people try to do bromine by only putting tablets in a floater and neglect adding the sodium bromide.)

Am currently using Brilliance System. Like the lack of chlorine smell plus no more breathing problems.

This is probably because your bromine is much lower.

However its nearly impossible to maintain free bromine

In a bromine system you are only testing total bromine.

without oxydizing every 2-3 days when the sun is shining - and we haven't even hit summer yet! Turning out to be very expensive.

Still a bromine system but it uses potassium monopersulfate (MPS) to shock. It still converts the bromide into active bromine sanitizer in exactly the same way as chlorine does. Fucntionally no different but the marketing hype of a chlorine free system sells it!(and it IS expensive!)

IMHO, a properly maintained chlorine spa has much less of a chemical odor than a bromine spa, but it does require daily maintenance to maintain the chlorine levels.

One of the biggest problems with bromine is that it is not stable in UV light. The dimethylhydantion in bromine tablets add a bit of UV stability over time if they build up high enough but create the same sort of problems seen in overstabilized chlorine systems. A three step bromine system (adding sodium bromide on filling, shocking with unstablized chlorine or MPS and using bromine tablets in a floater to maintain the bromine levels) might be the least maintenance (but bromine does have that 'choking' odor!) but you could also go with chlorine and add about 30 ppm cyanuric acid to help stabilize it against loss from UV. I would not go any higher than that in a spa and I would run the free chlorine levels at about 6-8 ppm if you go that route. You will have to manually chlorinate with an unstablized chlorine source daily to maintain your Free chlorine levels. Shock the system with chorine to about 15 ppm whenever the combined chlorine tests above .5 ppm. I would not use dichlor because it will cause the cyanuric acid levels to rise to quickly and lead to overstabilization. This will diminish the chlorine's sanitizing effectiveness and could allow pseudomonas to grow in the heated spa water. This is what causes 'hot tub itch'.

Hope this is helpful.

[Donaldor]

Thanks for the great info waterbear. I should have also mention that we only heat the spa prior to use, otherwise its stabilized at an ambient temperature.

Like the idea of going chlorine but daily maintenance may be an obstacle. I wonder if setting up some sort of feed system using an injection pump would allow me to take a few days off if I'm out of town. I worked in water treatment at one time and we used injection pumps extensively. Could probably run it off my existing pump controller as I think there's an extra set of relay contacts.

[waterbear]

You can get a peristaltic pump to dose liquid chlorine. I would not worry about ORP controllers but just use a timeclock for the dosing pump and test your water to adjust the settings. ORP controllers will have problem with the cyanuric acid.

[Donaldor]

What are your thoughts regarding an electronic chlorine generator such as that sold by Hayward? This device looks like it would dovetail right into my existing Hayward control system. I like the TPC EasyChem 100 system as well but looks like its only sold down under.

Thanks again for your input WB!

[waterbear]

Goldline Controls (Hayward) are, IMHO, one of the better SWGs on the market. Have one on my own pool and spa! (Goldline Aqualogic PS-8 automation and SWG system). If you have one of the Aqualogic automation units all you need to do is add the salt cell option. Pool Pilot is probably the most advanced SWG on the market and is an excellent unit and WaterMaid is the company that developed the technology in the first place and have the most years of experience. IMHO, these are the top three on the market and all have excellent customer support (which can't be said of some of the other brands out there).

[Johnny D]

Would you recommend one of these units for an above gorund spa like a Sundance? Seems like once you got it dialed in it woudl eliminate most of the daily maintainence.

[itabb]

I keep reading how MPS is expensive compared to shocking with Chlorine in a Bromine Spa. How do I shock with 6% bleach instead of MPS in a 500 gallon spa?